Depression and the Brain

We are more depressed than ever before.

In the US alone, data indicate that depression has tripled among adults, jumping from 8.5% to 32.8%, affecting 1 in every 3 American adults.

This is very concerning news, considering that depression does more than just make us feel sad and anxious. When suffering from depression, there are actual physical changes to the brain.

According to the National Institutes of Health, people suffering from depression lose gray matter volume, which is detrimental to our cognitive functioning as this means that our brain shrinks due to cortisol obstructing growth in new brain cells.

The neurobiology of depression

Depression was originally believed to be derived from an abnormality in serotonin (a natural mood stabilizer controlling happiness) and/or norepinephrine — the hormone that plays the role in your body’s flight or fight response. However, upon further investigation and research, scientists have discovered that this might not be painting the full picture.

There are chemical messengers, which include glutamate and GABA, between the nerve cells in the higher centers of the brain involved in regulating mood and emotion.” 

— John Krystal, MD, Chair of Yale’s Department of Psychiatry

Beyond serotonin and norepinephrine, the two neurotransmitters mentioned above — glutamate and GABA — also seem to play a part in regulating how the brain develops over time.

Chronic stress and anxiety – two attributes of depression – can cause the connections between these two neurotransmitters to break apart, and as a result, communication is muddled. This broken communication and connection are what scientists are believing to lead to the neurobiology of depression.  

Brain changes from depression

When we are depressed, there are legitimate changes to the brain that goes on, which can have a negative impact on our general cognitive and executive functioning.

Brain shrinkage — As mentioned above, depression can lead to structural changes in parts of the brain, from the hippocampus (memory, learning) , thalamus (information relay), amygdala (regulates emotion and memory), and prefrontal cortex (attention, emotional reaction). From depression, all of these can be heavily affected, with shrinkage in size. Depending on how long the depressive episode is, the amount these areas shrink differs. Shrinkage of any kind in those aforementioned parts is dangerous, as this results in reduced performance and functioning in those areas.

Reduced oxygen intake — For people that are depressed, there have been signs of reduced oxygen intake. This may be due to depressed people breathing differently on an unconscious level. Restricted oxygen can be bad for our brain, as it can lead to inflammation and brain cell death, which affect our overall development, memory, and mood.

Brain inflammation — While brain inflammation only happens from chronic stress and anxiety, it can be quite impactful on the brain once it does happen. Brain inflammation can lead to the death of brain cells, shrinkage, and reduced neuroplasticity — meaning the brain will be less likely to change and adapt as it ages, staying relatively the same without evolving.

How to deal with depression

From antidepressants to other medicine, there are plenty of ways to deal with depression. However, some of the ways below are more natural methods to go about reversing the effects of depression within the brain.

  • Cognitive behavioral therapy (CBT) — A form of psychotherapy, CBT helps to modify thought patterns and behaviors. It’s based on the idea that negative feelings are the result of current beliefs and behaviors instilled within us, which can be altered with enough conscious effort. By becoming more aware of your thought processes and the behaviors that are induced by such thoughts, you learn to take more control of your life. With the right therapist guiding you through, CBT has been noted to be an effective preventative method for depression.
  • Therapy — Even if it’s not CBT, therapy, in general, can help alleviate bouts of depression. Therapy is a great way to identify the patterns of thoughts and behaviors that affect your life negatively. You learn to process your feelings and emotions better, reflecting on them more carefully and understanding where stress may be coming from.
  • Regular exercise — According to a study in 2020 on exercising and brain plasticity, regular exercise has been shown to improve the overall structure of the hippocampus. Countless studies point to the benefits of exercising, with one 2019 research demonstrating how people who exercised three times per week for several weeks displayed far fewer symptoms of depression than those who didn’t.
  • Meditate — Meditation can help the brain be more focused, and improve attention, and memory, as well as gain a better grasp on emotions. Research has shown that meditation changes certain regions of the brain, alleviating areas such as the medial prefrontal cortex (mPFC). This is important to note as the mPFC riles up when people are stressed, and is an active area for people experiencing depression.

Meditation trains the brain to achieve sustained focus, and to return to that focus when negative thinking, emotions, and physical sensations intrude — which happens a lot when you feel stressed and anxious

— Dr. John W. Denninger, Director of Research at the Benson-Henry Institute for Mind Body Medicine